1. Field of the Invention
The present invention relates to a thermal printer, and more particularly to a thermal printer in which a recording paper is fed between a thermal head and a platen.
2. Description of the Related Art
There is a color thermal printer in which a color thermosensitive recording paper is used to obtain a full-color print. The color thermosensitive recording paper has a plurality of thermosensitive coloring layers stacked on a support member. Thermal recording is performed for the respective thermosensitive coloring layers of the recording paper by means of a thermal head in a frame sequential manner. In such a color thermal printer, a color thermosensitive recording paper is fed between a thermal head and a platen, and one of the thermal head and the platen is moved toward the other thereof to nip the recording paper. After that, thermal recording is performed for the recording paper by heating the thermal head.
Japanese Patent Laid-Open Publication No. 10-217518 discloses a color thermal printer of which size is reduced by projecting a part of a color thermosensitive recording paper to the outside of the printer at the time of printing. In this color thermal printer, a recording face of the recording paper is adapted to be directed downward so that a thermosensitive coloring layer of the recording paper is prevented from being fixed by the ambient light. For this, a thermal head is disposed under a conveyance passage of the recording paper. Further, a platen facing the thermal head and nipping the recording paper is disposed above the thermal head.
In conventional color thermal printers, if a color thermosensitive recording paper has a curling peculiarity, the recording paper abuts on a thermal head or a platen when the recording paper is fed between the thermal head and the platen. Thus, there arises a problem in that the recording paper is not properly forwarded between the thermal head and the platen. In a color thermal printer having a thermal head disposed under a conveyance passage, an upper face of the thermal head is provided with a heating element array comprising a plurality of heating elements. Due to this, jamming of the recording paper sometimes occurs because a leading edge of the recording paper forwarded between the thermal head and the platen is caught by the upper face of the thermal head. Otherwise, as to a seal-like color thermosensitive recording paper, a recording paper is peeled from a separation paper so that defect of printing, failure in conveyance and so forth are caused.
The above-mentioned problems may be solved by disposing a roll, which acts as feeding means for conveying the recording paper, at a position being higher than the thermal head. However, when the roller is disposed at the higher position than the thermal head, an abutting condition of the recording paper and the heating element array becomes worse. Therefore, there arises a problem in that a print image becomes unclear.